Self-tightening clamps have been utilized in the past for suspending objects, for example sheets of glass during treatment of the sheet. A typical such clamp is disclosed and described in U.S. Pat. No. 2,646,307 and which includes a stirrup having two gripping levers pivoted on the end of the stirrup and where the levers have a cam-shaped sheet engaging portion on their ends. The ends of the levers in turn are connected by arms to a suspension link. As constructed the levers of the device of that patent have no means for limiting movement of the cam-shaped portions towards each other such that the portions may dig into a hot deformable sheet an excess amount making automatic disengagement difficult. Further in clamps of this type, no means are provided for assuring that the stirrup supporting the levers will remain in alignment with the suspension link during engagement and disengagement, therefore making automatic engagement and disengagement difficult.
As a result production problems have arisen with prior art self-clamping devices in that the clamps do not always properly engage or clamp onto a sheet of glass or where it is difficult to automatically release a sheet once it has been fully clamped by the device.
It is therefore an object of the invention to provide for a self-tightening clamp which may properly engage and clamp a sheet of glass wherein the clamp will be stabilized in an angular position with respect to the sheet to insure that the clamp will properly engage the sheet and to further insure that the clamp may be easily opened with respect to the sheet.